Aryl styrene-based polymers are synthesized by the radical polymerization [for example, Vysokomol. Soedin., 8 (10), 1804 (1966)], anion polymerization [for example, Makromol. Chem., 117, 94 (1968)], cation polymerization [for example, Polymer J., 7 (3), 320 (1975)] or Ziegler-Natta polymerization [for example, J. Polymer Sci. A-1, 5, 2323 (1967)] and most of them have an atactic configuration but the above mentioned J. Polymer Sci. A-1, 5, 2323 (1967) reports those having an isotactic configuration by using a titanium trichloride-triethyl aluminum catalyst.
On the other hand, styrene-based polymers mainly consisting of a syndiotactic configuration are disclosed in the official publication of Japanese Patent Kokai No. 63-172705, official publication of Japanese Patent Kokai No. 63-172706 and official publication of Japanese Patent Kokai No. 63-172707. No examples of preparation, however, have yet been reported of a highly heat resistant aryl styrene-based polymer having a syndiotactic configuration.
Apart therefrom, the assignee has been previously successful in the development of a styrene-based polymer having high syndiotacticity and disclosed the same (official publication of Japanese Patent Kokai No. 62-104818 and official publication of Japanese Patent Kokai No. 62-187708).
Although this polymer is excellent in the heat resistance, resistance against chemicals and electric properties, the inventors have continued extensive investigations in order to further upgrade these characteristics and arrived at a discovery that an aryl styrene-based polymer having a syndiotactic configuration can be obtained by polymerizing a styrene derivative having an aryl group leading to completion of the present invention on the base of this discovery.
On the other hand, resins having good heat resistance and moldability are eagerly desired as a material of electric appliances and material of automobile parts. Therefore, a proposal has been made of a polystyrene mainly consisting of a syndiotactic configuration (official publication of Japanese Patent Kokai No. 62-104818, official publication of No. 62-187708 of the same and elsewhere) but it has a problem that the temperature range suitable for melt-molding (difference between the melting point and the decomposition temperature) is small to cause a difficulty in molding.
Although the said polystyrene has relatively good heat resistance, furthermore, resins having still higher heat resistance are desired which can withstand severe conditions.
The present invention has an object, by solving these problems, to provide a resin having excellent moldability with a wide temperature range suitable for melt molding and excellent heat resistance as well as an efficient method for the preparation thereof.